。
The arrow points the way to Tokyo.
Literal
Arrow [topic-は] Tokyo [to-へ] go road [obj-を] shows.
矢印 here is the visual arrow-sign (road sign, symbol), not a physical arrow — a useful lexical point. 東京へ行く is a relative clause modifying 道 ('the road that goes to Tokyo'), with へ as the directional particle. 示す ('show, indicate, point to') is the verb of pointing out or demonstrating.